package pers.bc.utils.file;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import pers.bc.utils.throwable.MylbcException;

/**
 * 利用文件头来实现的一些文件类型的方法封装
 * @qualiFild com.pub.utils.file.FileTypeImpl.java<br>
 * @author：licheng<br>
 * @date Created on 2019-8-12<br>
 * @version 1.0<br>
 */
public class FileTypeImpl
{
    
    public final static Map<String, String> FILE_TYPE_MAP = new HashMap<String, String>();
    
    static
    {
        FILE_TYPE_MAP.put("jpg", "FFD8FF"); // JPEG (jpg)
        FILE_TYPE_MAP.put("png", "89504E47");  // PNG (png)
        FILE_TYPE_MAP.put("gif", "47494638");  // GIF (gif)
        FILE_TYPE_MAP.put("tif", "49492A00");  // TIFF (tif)
        FILE_TYPE_MAP.put("bmp", "424D"); // Windows Bitmap (bmp)
        FILE_TYPE_MAP.put("dwg", "41433130"); // CAD (dwg)
        FILE_TYPE_MAP.put("html", "68746D6C3E");  // HTML (html)
        FILE_TYPE_MAP.put("rtf", "7B5C727466");  // Rich Text Format (rtf)
        FILE_TYPE_MAP.put("xml", "3C3F786D6C");
        FILE_TYPE_MAP.put("zip", "504B0304");
        FILE_TYPE_MAP.put("rar", "52617221");
        FILE_TYPE_MAP.put("psd", "38425053");  // Photoshop (psd)
        FILE_TYPE_MAP.put("eml", "44656C69766572792D646174653A");  // Email [thorough only] (eml)
        FILE_TYPE_MAP.put("dbx", "CFAD12FEC5FD746F");  // Outlook Express (dbx)
        FILE_TYPE_MAP.put("pst", "2142444E");  // Outlook (pst)
        FILE_TYPE_MAP.put("xls", "D0CF11E0");  // MS Word
        FILE_TYPE_MAP.put("doc", "D0CF11E0");  // MS Excel 注意：word 和 excel的文件头一样
        FILE_TYPE_MAP.put("mdb", "5374616E64617264204A");  // MS Access (mdb)
        FILE_TYPE_MAP.put("wpd", "FF575043"); // WordPerfect (wpd)
        FILE_TYPE_MAP.put("eps", "252150532D41646F6265");
        FILE_TYPE_MAP.put("ps", "252150532D41646F6265");
        FILE_TYPE_MAP.put("pdf", "255044462D312E");  // Adobe Acrobat (pdf)
        FILE_TYPE_MAP.put("qdf", "AC9EBD8F");  // Quicken (qdf)
        FILE_TYPE_MAP.put("pwl", "E3828596");  // Windows Password (pwl)
        FILE_TYPE_MAP.put("wav", "57415645");  // Wave (wav)
        FILE_TYPE_MAP.put("avi", "41564920");
        FILE_TYPE_MAP.put("ram", "2E7261FD");  // Real Audio (ram)
        FILE_TYPE_MAP.put("rm", "2E524D46");  // Real Media (rm)
        FILE_TYPE_MAP.put("mpg", "000001BA");  //
        FILE_TYPE_MAP.put("mov", "6D6F6F76");  // Quicktime (mov)
        FILE_TYPE_MAP.put("asf", "3026B2758E66CF11"); // Windows Media (asf)
        FILE_TYPE_MAP.put("mid", "4D546864");  // MIDI (mid)
    }
    
    /**
     * Created on 2010-7-1
     * <p>
     * Discription:[getFileByFile,获取文件类型,包括图片,若格式不是已配置的,则返回null]
     * </p>
     * 
     * @param file
     * @return fileType
     * @author:[shixing_11@sina.com]
     * @throws MylbcException 
     */
    public final static String getFileType(File file) throws MylbcException
    {
        String filetype = null;
        byte[] b = new byte[50];
        try
        {
            InputStream is = new FileInputStream(file);
            is.read(b);
            filetype = getFileTypeByStream(b);
            is.close();
        }
        catch (IOException e)
        {
            throw new MylbcException(e);
        }
        return filetype;
    }
    
    /**
     * 
     * *********************************************************** <br>
     * 说明：
     * @see
     * @param b
     * @return
     * @String
     * @author licheng
     * @date Created on 2019-7-28
     * @time 下午8:09:41
     * @version 1.0 <br>
     ************************************************************* <br>
     */
    public final static String getFileTypeByStream(byte[] b)
    {
        String filetypeHex = String.valueOf(getFileHexString(b));
        Iterator<Map.Entry<String, String>> entryiterator = FILE_TYPE_MAP.entrySet().iterator();
        while (entryiterator.hasNext())
        {
            Map.Entry<String, String> entry = entryiterator.next();
            String fileTypeHexValue = entry.getValue();
            if (filetypeHex.toUpperCase().startsWith(fileTypeHexValue))
            {
                return entry.getKey();
            }
        }
        return null;
    }
    
    /**
     * *********************************************************** <br>
     * 说明：
     * @see
     * @param b
     * @return
     * @String
     * @author licheng
     * @date Created on 2019-7-28
     * @time 下午8:09:48
     * @version 1.0 <br>
     ************************************************************* <br>
     */
    public final static String getFileHexString(byte[] b)
    {
        StringBuilder stringBuilder = new StringBuilder();
        if (b == null || b.length <= 0)
        {
            return null;
        }
        for (int i = 0; i < b.length; i++)
        {
            int v = b[i] & 0xFF;
            String hv = Integer.toHexString(v);
            if (hv.length() < 2)
            {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }
}
